Telegraph system.



1. H. BELL. TELEGRAPH SYSTEM.

APPLICATION FILED MAY 16. 1916.

Patented J an. 16, 1917.

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//7 Ven for. gfof/f7 /7. 562// which- "JOHN H. BELL, or EAsrOEANGEEEw JEESEYQASSIGNOE To WESTERN. ELECTRIC COMPANY, INCORPORATED, 0E NEW YORK, 1v, 'A 'CORPORATION o'E Y'OE'E.

TELEGEAPH SYSTEM.

To all whom t may concern Be it known that I, JOI-IN I-I. BELL, a subject of the King of vGrreat Britain, residing at East Orange, in thecounty of-EsseX and State of New Jersey, have invented Vcertain new' and useful Improvements in Telegraph Systems, of which the following is a full; clear, concise, and exact description.

This invention relates to telegraph systems, and mo-re particularly j to `improvements in systems for repeating or relaying telegraphic signals, diil'erentiated by changes of polarity andcurrentstrengths from one line circuit section into another line circuit section, or from one line' section into a plurality of other line sections, 'the repeating operations taking place automatically andin a reciprocal manner withrrespect to a plurality of line sections grouped for service of this character. Y C

The principal object of this invention is to provide a simplified equipment 'of devices and circuits to affordeconomy in the vmatter of apparatus and current consumption, and to insure greater reliability inthe operation of a repeating system of the above type.

A further object'of this invention is to provide that the repeating equipment of one line section may be typical of the repeating equipment required by each one of a number of other line sections employed -therewith in a repeating'system, and to dispense with local circuits or equipment common to a plurality of such line sections. l

In accordance with this invention, each line section is provided with al group of four llne relays, whereby, in response to polarity and strength variable telegraphic signals primarily set up in any one' of the line sections, the relay group of the other line sections is thereby disabled while the latter line sections are joined one withanother and receive repeated impulses of current from sultable current sources at the repeating station. As repeated, the impulses correspond to the telegraphic signals rset up Vin the primarily active line section.

This invention is illustrated diagrammatically in the accompanying drawing, in

Figure l represents a repeating equipment for two line circuits or sections, and Fig. 2 represents a repeating equipment suitable'for three line sections. l p

Referring 'to the drawin`g,it will be noted Specification of Lettersv Patent.

that live distinctly grouped equipments, comprising four line relays' each, are re- Patented eTanic,191W." Y Application 1ed May 16, 1916. A Serial No. 97,762.

spectively indicated by reference characters I A, B, C, D and E, and `that five line circuit sections designated l, 2, 3, 4 and v5 rare operatively included with respective ones of these relay groups. It will also be notedin Fig. l that the relays and connections in the group A are typical of the relaysand connections comprisingthe group B, and further, that' when-telegraphic signalsare primarily active inthe line section l, thev relays in the group A are responsive to disable the relays in the group B, and also to repeat telegraphic signals from the-line section l into-the line section 2. Accordingly, inresponse to telegraphic vsignals primarilysetV up' in theline section 2, the relays in group B are activefto disable theV relays of .the

Y group A,vand .to repeatfthe telegraphic signals from the line 2 into the-line l. In a like mannen-the relays and connections of the group C in Fig. 2 are respectively typical of the relays and connections comprising the groups D and E of the vsame figure. The relays in group C become active ,under signaling impulses in the line 3 to disable vthe relays of the groups D and E and to repeat the telegraphic signals from the line section 3 into the line sections 4 and 5: And

conversely, the group of relays'D acts for 1 the-line 4 to disablethe relay groups C and E, and to repeat signals from the line 4l into the lines 3 and'5. And, in turn, the relays in vgroup E act for the line 5 to disable the group equipments C and D, and to repeat signals from the line 5 into the lines 3 and'll.

In more specifically describing the operation of this system, let it be assumed-that the line sections l and 2 extendV to stations equipments for transmitting andV receiving messages by well-known methods are provided. And let it be further assumed that the characteristic form of the transmitted and received current impulses may correy (not shown) at which suitable telegraphic spond with predetermined periods of posiactive, the current impulses thereby set up in the line 1 may be traced therefrom through the Vcontacts 22 of a relay 17 in the group B, thence over a conductor 6 to the group A, there continuing through the winding of a relay 7, the winding 0f a relay 8, the winding of a relay 9, thence to the earth connection through the winding of a relay 10. The relays 7 and 8 are adapted to respond to either direct current or to alternating currents, and, therefore, may be termed universal current relays. The characteristics of the two relays differ, however, one from the other. The relay 7 is adapted to Operate quickly under the 1niiuence of current, but to release slowly o-n cessation of current; the adjustment of this 'relay is such thatit will respond to all signaling currents which may pass through its windings, as the impulses of strong current or the impulses of weak current. The relay 8 is, on the other hand, adapted to respond quickly underV current action, and also to release quickly when current ceases therethrough. The adjustment of this relay is such, however, that it will not respond to impulses of weak current, but will remain inert until operated by impulses of strong current. The relay 9, as indicated by the conventional polarity sign, only responds to currents of negative character, while the relay 10, as conventionally labeled, only responds to currents of positive character. These polarized relays are each adjusted to respond to currents of all strengths when of the proper respective polarity, and their armatures are biased (by means not shown) to normally maintain the associated contacts open, and to cause these contacts to separate at each cessation of operating current through their windings.

Let it now be assumed that an impulse of weak negative current is present in the. line circuit 1, thereby operating the relays 7 and 9, while the relays 8 and 10 remain inert. The contacts l12 of the relay 7, now separated, disconnect the serially connected relays 17, 18, 19 and 20, which comprise the group B, while the closing of the contacts 13 of the relay 7 connects the line circuit 2 by way of a resistance unit 11 to a bus conductor 14, which is common to the con-` tacting armatures of the polarized relays 9 and 10. Therefore, as the contacts of the polarized relay 9 are now closed, the negative side of a grounded current source 15 is connected through the resistance unit 11,`

over the path just traced to the line circuit 2. If, now, an impulse of positive current kis transmitted from the distant station on the line 1,' the negative relay 9 restores to separate its contacts, while the positive relay 10 is operated to close its-contacts, and thereby connect the positive side of a grounded source o-f current 16 also by way of the resistance unit 11 to the line circuit 2. The universal current relay, 7 as described, remains operated under both the negative and the positive impulses of current received over the line 1. The effect of an impulse of negative current having the required increased strength, if now received from the line circuit l, first assists in restoring the positive relay 10, then causes the operation 0f the marginally adjusted relay 8 and the negative relay 9. The closing of the contacts of the relay 8 establishes a short circuit around the resistance unit 11; therefore the negative battery 15 is connected through the contacts of the relay 9 and the contacts of the relay 8 to the line circuit 2, the relay 7 remaining operated as described. The shunting out of the resistance unit 11 by the contacts of the relay 8 permits the full potential of the battery 15 to reach the line circuit 2, and therein set up a current of a strength corresponding to that of the current receivedv over the line circuit 1 by which the marginal relay 8 was caused to operate. In asimilar manner, a strong im Vpulse of positive current from the line circuit 1 also operates the relay 8 to again shuntthe resistance unit 11, while the relay l0 responds to connect the positive battery 16 in full potential to the line circuit 2. And conversely, current impulses of characteristically reduced strength, transmitted through the circuit of the line 1 as first described, fail to operate the relay'8, thereby permitting the resistance unit 11 to be present in the common path by which current from either the negative battery 15 or the positive battery 16 reaches the line circuit 2, thus compensating for and reducing the potential of the working current from these repeater batteries. In this manner, changes of current strength inthe line circuit 1 are evactlyv responded to by the repeating system, and translated in corresponding strength into the line circuit 2.

When messages are being transmitted from the station assumed to be present on the Yline circuit 2, the signaling currents therein present may be traced through the contacts 12 of the relay 7,k thence through the serially connected relays 17, 18, 19 and 20, comprising the group B, to the earth connection. For impulses of current of either polarity in the line circuit 2, the relay 17 responds to separate its contacts 22, thereby disconnecting the relays of the group A, while the closing of its contacts 23 connects the common or bus conductor 24 of the polarized relays 19 and 20, by way of a resistance unit 21, to the line circuit 1. The manner in which telegraphic signaling impulses are translated from the line circuit 2 into the line circuit l by means of the relay group B corresponds in every detail with the operations of the relays inthe group A in translating-signalsfrom the line :circuit 1 into the line circuit 2, as already described.

Referring to F ig. 2 of the drawing, let it be assumed thattelegraphic signals of the character described are being setup by a transmitter (not shown) on the lineI circuit 3. The path of such current impulses may be ltraced from the line conductor 3, through the contacts 52 of a relay 47, a conductor 56, the contacts 42 of arelay 37,l a conductor 57, thence through the Winding of each oneof the four serially connected relays 27', 28,29 and 30, comprising repeating relay group'C, to the earth connection. The universal current relay 27 continues operated under each character of signaling current' as already described for the corresponding relays 7 and 17 of Fig. 2. Separationv of` the contacts 32 of the' relay 27 disconnectsthe `relays compris'ing the group D., and the separation of the contacts 33`of this relay disconnects the relays of the group E, While the closing lof the contacts 34 and 35 of this relay joins the line circuits 4 and 5, one with the other, and, by Way of a resista-nce unit 31, also with the bus conductor 36, which is common to the contacting armatures of the polarized relays 29 and 30. In response to negative and positive impulses of current in the line circuit 3, the polarized relays 29 and 30 respectively connect the negative battery 15 or the positive battery 16 with the line circuits 4 and 5. The marginally adjusted universal current relay 28 only responds to currents in excess of a predetermined strength, and its contacts act to short-circuit the resistance. unit 31. This combination corresponds Wlth the relay 8 and the com-` pensating resistance unit l1 of the group A,

and, 1n this case, the resistance 31 is calibrated to so compensate the current which will be repeated into the lines 4 and 5 that each one of these lines will receive a current of a strength corresponding to the originating current impulse transmitted through the line 3. A full strength current impulse in the line circuit 3 causes the relay 28 to operate and shunt out the resistance unit 31, thereby permitting current to be repeated at the full potential of the batteries 15 and 16 into the lines 4 and 5.

Signaling current action primarily taking place in the line circuit 4 completes circuit therefrom over the contacts 32 of the relayV 27, a conductor 4.5, the contacts 53 of a relay 47, a conductor 58, thence through the serially connected windings of the relays 37,

38, 39 and 40 comprising the repeating group D, to the earth connection. The contacts 42 and 43 of the universal current switching relay 37 disconnect the relay groups C and E respectively, While the contacts 44 and-45 of this relay connect the line circuits 3 and Y 5 through a resistance unit 41 with the commonly connected contacting armatures of the polarized relays 39 and 40. The marginally adjustedrelay 38 and the relaysV 39 and40 of this group act in a mannersimilar tojthatalre'ady described for the relay group C to repeat signalingV impulses from the line circuit 4 into the line circuitsl 3 and 5. Repeated currents from the batteries in group D, after passingthe contacts 44 and 45, rev sp'ective'ly, of the relay 37, reach the line cir- 1 cuit l3 byway of the contacts 52 of therelay 47, andthe line circuit 5 by Way of the contacts-133 of the relay '27.y

Originating signaling" current impulses when transmitted over the line circuit 5 mayl be tra'cedtherefrom over thecontacts 33 of vthe relay 27 a conductor 59, the contacts 43 of a relay 37, thence Vthrough the windings of the iser'ially connected relays '47, '48, 49

Y and `50, comprising the'relay group'l'tothey earth connection. The contacts 52 and -5'3fof the relay 47-disconnectthe relay groups' C and D, While the vcontacts 54v and 55l of v this relay connect the line" circuitsy 3 and 4 4. Repeated currents from the batteries of this group, after passing the contacts 54` and 55, respectively, of the relay 47, reach the line circuit 3 directly, and the line circuit 4 after traversing the conductor 46 and the contacts 32 of the relay 27.

Although several sources of current have Y for convenience been shown in the drawing, it will be understood that all correspondingly poled sources of current may be, and preferably are, one and the same source of current. Y

' In this system, the number ofV line circuits capable of interacting one With another for the reciprocal repeating of telegraphic sig- Y nals may be extended by merely placing ad- Y ditional contacts on the switching relays indicated as relays 7, 27 etc.

What is claimed is: Y 1. In a" telegraph repeating system,

` sources of current, a plurality of lineV sections, a plurality of line relays for each one of said line sections for repeating telegraphic signals respectively into Vthe other ones of said line sections, and a repeating line relay for each line section adapted to remain inert when traversed by signal impulses of strengths less than a predetermined amount and to respond only to cur'- rentsv in excess of the predetermined strength. Y Y

2. In a telegraph repeating system, sources of current, a plurality of line sections, a plurality Ofiline relays for each line section to repeat telegraphic signals respectively Vfroni'one line into the other lines, a current strength regulating means for each line section, and a line relay for each line section to control the operativeness-of said regulating means. Y

3. In a telegraph repeating system, sources of current, a plurality of line sections, a plurality of line relays for each one of said lines for respectively repeating telegraphic signals from any` one of said lines into the other lines, an additional line relay for each of said line sections` inert under current of one strength but operative under currents of another strength, and means controlled by the last mentioned relay to respectively cause the strength of repeated currents to correspond With the strength of theJ current received through said additional re ay. l

4. In a telegraph repeating system,

sources ofv current, a plurality of line relay groups each comprising a universal current slow-release relay, a universal current marginally adjusted relay and a plurality of polarized relays, a line section for each of said relay groups, contacts operated by the switching relay of any group to disable the relays of the other groups and to join the line sections of the disabled groups one with another, contacts operated by the polarized relays for including said sources of current with said joined line circuits, a resistance unit for each relay group included in the path by Which current from said sources may reach the joined line circuits, and contracts loperated by said marginally adjusted relay for controllingthel operativeness of said resistance unit.

In Witness whereof I hereunto subscribe my name this 12th day of May, A.. D. 1916.

JOHN H.v BELL.

Sonics of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

